A spacecraft destined to become the fastest manmade object in history is set for launch on Friday on a mission that will end in a high-speed crash into the largest planet in the solar system. Nasa’s 1bn Juno space probe is bound for Jupiter on a mission to peer through the clouds of the Jovian atmosphere and deep into the planet’s interior.Before Juno arrives at its destination, rocket motors will fire up and set the satellite spinning like a three-bladed propeller so that each of its scientific instruments can get a regular and clear view of the planet.The five-year journey will bring Juno in over the north pole of Jupiter to begin the first of 33 orbits at speeds of up to 160,000kph. To minimize damage from Jupiter’s intense radiation fields, the spacecraft will follow a highly elliptical (椭圆的) orbit that goes far out into space before returning low over the north and south poles.The spinning satellite will photograph Jupiter’s spectacular aurora (极光) and map its intense magnetic and gravitational fields for a year in a bid to understand the planet’s formation and the inner workings that make it one of the most extraordinary bodies in the solar system.“Juno will help us understand how the solar system formed, and how all the planets formed.” said Jack Connerney, deputy principal investigator on the Juno mission at Nasa’s Goddard Space Flight Centre in Maryland. “After the formation of the sun, the vast majority of mass left over in the solar system resides in Jupiter. The planet is so massive that none of the material that was originally there could escape its gravity, so Jupiter is effectively a sample of the primitive solar nebula (太阳星云) that all the planets formed from.”A major question Juno will seek to answer is the nature of the dynamo that generates Jupiter’s powerful magnetic field, which is 20,000 times stronger than that of the Earth. On our home planet, the magnetic field is produced by a spinning core of molten iron.1. What will the spacecraft Juno end in?A) Going deep into Jupiter’s interior.B) Rotating in orbit around Jupiter.C) A steady landing on Jupiter.D) A high-speed crash into Jupiter. 2. What is the purpose of Juno following a highly elliptical orbit?A) To avoid damage by the radiation fields. B) To return low over the south poles.C) To get a clearer view of the planet.D) To stay away from the north poles.3. What will Juno do to help us understand how Jupiter formed?A) Photograph spectacular stars surrounding the planet.B) Peer through the vast majority of mass left over there.C) Map the magnetic and gravitational fields of the planet. D) Measure the distance between Jupiter and its satellite.4. What do we know about Jupiter according to Jack Connerney?A) It is made from a large amount of mass.B) It is very massive with high gravity. C) It is actually a sample of other primitive planets.D) It has a dynamo generating powerful magnetic fields.5. What is the main idea of the passage?A) Juno spacecraft arrived at Jupiter after a five-year journey.B) Juno space probe will draw maps of Jupiter.C) Juno space probe prepares for its mission to Jupiter. D) New frontiers of the solar system will be explored in the future.

A spacecraft destined to become the fastest manmade object in history is set for launch on Friday on a mission that will end in a high-speed crash into the largest planet in the solar system. Nasa’s $1bn Juno space probe is bound for Jupiter on a mission to peer through the clouds of the Jovian atmosphere and deep into the planet’s interior. Before Juno arrives at its destination, rocket motors will fire up and set the satellite spinning like a three-bladed propeller so that each of its scientific instruments can get a regular and clear view of the planet. The five-year journey will bring Juno in over the north pole of Jupiter to begin the first of 33 orbits at speeds of up to 160,000kph. To minimize damage from Jupiter’s intense radiation fields, the spacecraft will follow a highly elliptical (椭圆的) orbit that goes far out into space before returning low over the north and south poles. The spinning satellite will photograph Jupiter’s spectacular aurora (极光) and map its intense magnetic and gravitational fields for a year in a bid to understand the planet’s formation and the inner workings that make it one of the most extraordinary bodies in the solar system. “Juno will help us understand how the solar system formed, and how all the planets formed.” said Jack Connerney, deputy principal investigator on the Juno mission at Nasa’s Goddard Space Flight Centre in Maryland. “After the formation of the sun, the vast majority of mass left over in the solar system resides in Jupiter. The planet is so massive that none of the material that was originally there could escape its gravity, so Jupiter is effectively a sample of the primitive solar nebula (太阳星云) that all the planets formed from.” A major question Juno will seek to answer is the nature of the dynamo that generates Jupiter’s powerful magnetic field, which is 20,000 times stronger than that of the Earth. On our home planet, the magnetic field is produced by a spinning core of molten iron.1. What will the spacecraft Juno end in?A)  Going deep into Jupiter’s interior.B)  Rotating in orbit around Jupiter.C)  A steady landing on Jupiter.D)  A high-speed crash into Jupiter. 2. What is the purpose of Juno following a highly elliptical orbit?A)  To avoid damage by the radiation fields. B)  To return low over the south poles.C)  To get a clearer view of the planet.D)  To stay away from the north poles.3. What will Juno do to help us understand how Jupiter formed?A)  Photograph spectacular stars surrounding the planet.B)  Peer through the vast majority of mass left over there.C)  Map the magnetic and gravitational fields of the planet. D)  Measure the distance between Jupiter and its satellite.4. What do we know about Jupiter according to Jack Connerney?A)  It is made from a large amount of mass.B)  It is very massive with high gravity. C)  It is actually a sample of other primitive planets.D)  It has a dynamo generating powerful magnetic fields.5. What is the main idea of the passage?A)  Juno spacecraft arrived at Jupiter after a five-year journey.B)  Juno space probe will draw maps of Jupiter.C)  Juno space probe prepares for its mission to Jupiter. D)  New frontiers of the solar system will be explored in the future.